Goodness, where to begin, where to begin. Well, I play in an OD&D game once a week; a Hero System/Champions game about once a month; a MegaTraveller game a couple times a year; and a GURPS game which is on hiatus.
In the works is either a Villains & Vigilantes game or a Marvel Super Heroes game. There's also a possibility of playing a new GURPS game, a DragonQuest game (my favorite), or a homebrew game later this year.
I love playing all sorts of games, playing one game, or even one game system, starts to get stale after awhile.